Speaking on Our Cilla, a tribute programme celebrating the late star, he also said she was troubled by ailments commonly associated with old age.

"Her hearing had started to go so she had to start wearing hearing aids. Typical of my mum, she wouldn't wear them. The thing that really affected her physically was her arthritis," he admitted.

Willis, who was also her manager, talked about the last day he spent with his mother at her home in Spain.

"I'd gone for a jog, gone for a swim and stuff. She was sitting around having a glass of champagne, killing herself laughing at Jeremy Kyle - without the hearing aids obviously - so it was blaring out across Marbella.

"We hung out and at about 1 o'clock, I said I was going to do a shop. I said goodbye and that was the last time I saw her."

Black died of a stroke on August 1 after falling and hitting her head at her Spanish villa.

The 72-year-old was sunbathing when she lost her balance, fell, and hit her head, which knocked her unconscious.

Black never remarried after losing husband Bobby Willis to cancer in 1999.

The couple, married for 30 years, had three sons and a daughter, Ellen, who died after being born prematurely.

Willis revealed her heartache over his father's death.

"It was so difficult for her just to acknowledge it," he said.

His younger brother Ben added: "Dad was 57 when he passed away, and that hit everyone. It knocked mum for six."

On the same subject, Joan Collins (inset) revealed: "She was looking for a boyfriend.

"I'd say, 'I think I might know someone' and she'd say, 'No, I don't really want one - I can't forget Bobby. Sometimes I feel like I want one and sometimes I don't'."